Ammonia is a byproduct of poultry excretion. Studies have shown that maintenance of low ammonia levels in industrial poultry houses is an important factor in increasing processing yield and feed efficiency, reducing bird stress and disease, and improving bird uniformity. Birds subject to high levels of ammonia weigh less, on average, than birds growing in low levels. Additionally, there is a greater spread in bird weight, and greater numbers of significantly undersized birds, making processing more difficult. High ammonia levels also negatively affect bird welfare at minimum and major levels. Levels above 35 parts per million (ppm) may adversely affect birds' growth, respiration, and disease immunity over time. At ammonia levels above 50 ppm, the spread of viruses, like Newcastle disease virus, can accelerate exponentially in a flock to the point where the whole flock can be lost. Conical lesions also dramatically increase at ammonia levels above 50 ppm. Above 100 ppm, birds may face immediate life threatening danger if action is not taken.
In order to control the amount of ammonia exposure, industrial poultry houses are ventilated based upon the levels of ammonia found in such poultry houses. However, humans vary in their ability to smell ammonia at levels below 50 ppm. Ammonia is currently managed by taking occasional point measurements using disposable colormatic tubes, and/or by tracking poultry house humidity as a loose proxy for ammonia, and then trying to set ventilation regimens accordingly. Such a process is burdensome, since it requires constant manual monitoring and adjustment. Further, ventilation can quickly become ineffective, particularly at nighttime. The building's lighting, ventilation, heating, humidity, and other parameters are typically adjusted automatically by a controller. The controller generally reduces ammonia levels by increasing ventilation, but excessive ventilation can reduce temperature inside the building, also negatively impacting bird health and increasing energy costs.
Therefore, there is a need for a real-time continuous ammonia sensor that can be used to continuously optimize ventilation. Further, there is a need for the real-time ammonia sensor to function in an automated feedback loop that keeps ammonia levels in the desired range using minimum ventilation.